Twine and process of preparing the same



. y 3, 1955 J. c. PULLMAN 2,707,367

TWINE AND PROCESS OF PREPARING THE SAME Filed Feb. 21, 1951 2Sheets-Sheet l INVENTOR mar/ c, Fuzz/v4,

2%. T- A ATTORNEY May 3, 1955 J. c PULLMAN 2,707,367

TWINE AND PROCESS OF PREPARING THE SAME Filed Feb. 21, 1951 2Sheets-Sheet 2 INVENTOR.

JOSEPH G. PULL/WIN,

ATTORNEY United States Patent TWINIE AND PRGCESS OF PREPARING THE SAMEJoseph C. Puliman, Stamford, Comm, assignor t American Cyanamid Company,New York, N. Y., a corporation of Maine Application February 21, 1951,Serial No. 212,065

11 Claims. (Cl. 57-440) This invention relates to a process. forproducing tape and/ or twine and, more particularly, to a process ofproducing glass fibrous strand'twine in which the glass strands areembedded in an adhesive material coated on a paper web, covered withanother layer of paper to form a fiat assembly and twisting saidassembly into a twine. Still further, this invention relates to aprocess .for preparing twine in which the flat assembly mentionedhereinabove is pressed so that the paper webs form corrugations with theglass strands prior to the twisting of the paper strand assembly to formthe twine.

One of the objects of the present invention is to produce a glass twinewhich will have general utility as a twine but which will beparticularly useful as a binder twine and baler twine. A further objectof the present invention is to produce a glass'twine which can bereadily substituted for natural twines such as those generally referredto as sisal twines. A still further object of the present invention isto produce glass twine by superimposing a plurality of parallel glassfibrous strands. on a paper web coated with an adhesive material,embedding the strands into the adhesive coating on the paper andcovering said strands with another paper web, uniting the strands, paperand adhesive into a hat assembly, thereutter twisting the assembly intoa twine. A still further object or" the present invention is to applypressure to the aforementioned fiat assembly in the course of the webassembly production so as to form corrugations with the strands andpaper web prior to the twisting of. the paper-strand into a twine. Astill further object of the present invention is to use as the adhesivematerial a thermosetting synthetic resin adhesive wherein the processfor the manufacture of the twine can be further modified after the twinehas been formed by adding the step of heating the twine so as to curethe thermosetting resin in. the twine. These and. other objects of thepresent invention will be discussed more fully hereinbelow.

Natural twine generally referred to as sisal twine is becomingincreasingly short in supply and the .price of said natural twine isincreasing steadily so that it is becoming a virtual necessity to find asynthetic twin'ewhich will be satisfactory for all of the generalapplications to which the natural twine is put. I have discovered that Ican combine a plurality of parallel glass fibrous strands with anadhesive coated paper web and cover the strand embedded adhesive coatedpaper with an additional layer of paper andform a twine which will havegreater strength per unit weight than the natural twine and yet can beproduced for far lower cost than the cost of natural twine. 'lIhe glassfibrous strands which may be used in the practice of the process of thepresent invention are made up of a great plurality of individual glassfilaments which are combined to form the strand. The process for thepreparation of these glassfibrous filaments and strands well known inthe art as represented by the U. S. Patents 2,133,236, 2,133,238, and2,175,225, amongst others. These filaments are generally'of extremelysmall diameter in the order of. magnitude of about 0.0002- LIA ice

0.0004 inch and are combined to form :a strand having a diameter orabout 0.04 inch since there are generally about 200 or more filamentsused to form. a single strand. These glass strands have exceedingly hightensile strength and, in fact, have greater tensile strength than steelwire per unit weight. These strands, on the other hand, cannot be useddirectly to form twine because they do not have the flexibility whichsteel wire has nor do they have the flexibility which natural fibrous:twine has. A further shortcoming of the glass fibrous strands resides inthe fact that, if a twine were to be made from the glass strands withoutany protective coating surrounding the strands, the continuous rubbingof one strand against the other would result in a breakdown of theindividual strands and eventually a breakdown of the entire twine. Astill further shortcoming of ordinary glass strand twine resides in thefact that the flexibility in small arcs is so low and the attrition sogreat that it is nearly impossible to produce knots having adequate knotstrength with such twine without experiencing continuous breaks in thetwine. This is due to the sharp, sudden curve through which the twine isbent in knot tying. I have discovered that by coating a paper web withan adhesive composition, superimposing a plurality of parallel glassstrands on the paper web, embedding the strands in the adhesiveon theweb and covering the strand embedded paper with another layer of paperto form a fiat, unitary assembly, I can twist said assembly into a twinewhich can be knotted and tied and which has extremely marked flexibilityand which strands being separately isolated from one another with theprotective coating of adhesive have no opportunity to rub against oneanother, which rubbing would normally result in the disintegration ofthe twine.

There are a plurality of ways in which this twine may be fabricated.Each of these minor departures from the essential concept of theapplicant are mere modifications, a few of which are set forthhereinbelow. Basically, it is preferred that the adhesive material beapplied directly to the paper web before the glass strands are appliedto the paper but if one so desired, the adhesive could be applied afterthe strands had been superimposed on the paper web or the adhesive couldbe applied to the web simultaneously with the glass strands or the glassstrands. could be coated with the adhesive composition and thereafterthe resin coated strands could be applied to the paper web.

A still further embodiment of this invention resides in themodification, wherein the glass fibrous strands are placed in parallelpositions on approximately one-half the width of the resin coated webwhereupon the web can be folded by means of a plow-like device so as tocover the strands and to form a flat, unitary assembly of paper,adhesive and glass fibrous strands. Still further, one could superimposea great plurality of fibrous strands on a wide paper web coated withadhesive and thereafter superimposing a second sheet on the strandembedded lower web and by slitting this wide web assembly into aplurality of narrower webs of desired width, one could proceed to twisteach of the narrower webs into the desired glass twine. Still furtherand, as a preferred embodiment of the present invention, one could makeuse of a pressing device in the nature of a pair of rollers covered witha resilient material which would force the upper and lower paper webstogether to form corrugations with the glass strands. Care must be takenin the selection of the pressure rollers to insure that the fibrousstrands are not damaged while the unitary assembly is being pressed intoa corrugated form. For this. reason, it is advisable to use a combingwheel which is firm and resilient and yet sufficiently pliable so. as toavoid damaging the strands. Still other embodiments of this inventionwill become obvious to anyone skilled in the art and, for this reason,further specific enumeration of detail is considered unnecessary. Eachof these embodiments are intended to be included within the scope of theappended claims.

Reference is made to the accompanying drawings which serve to illustratefurther the concepts of the present invention.

Fig. l is a side elevational view of a suitable arrangement for thepreparation of the tapes to be used in the twine fabrication. Fig. 2 isa perspective view of a part of Fig. 1 showing in greater detail thefabrication of the tape to be used ultimately in the twine manufacture.Fig. 3 is a front elevational view of the rubber covered rollers used topress the upper and lower webs together with the glass strands andadhesive therebetween. Fig. 4 is a side elevational view of Fig. 3. Fig.5 is a perspective view of a resin coated web upon which glass strandshave been superimposed in readiness for the subsequent steps in thetwine fabrication. Fig. 6

is a perspective view of one portion of Fig. 5 in which the lower web isfolded over the glass strands that are embedded in the adhesive on theweb. Fig. 7 is a cross sectional view of a section of the tapeillustrated in Fig. 6 or 2. Fig. 8 is an enlarged cross sectional viewof Fig. 6 after the tape has been passed through the companion rubbercovered rollers to form the corrugations. Fig. 9 is an enlarged crosssectional view of a portion of Fig. 8. Fig. 10 is a perspective view ofthe claimed product, showing the twisted structure of the twine with across-sectional view of the end thereof.

In Fig. l the symbols are used to identify the following componentsillustrated: 1 is the roll of paper tissue used as the upper web. 5 isthe roll of paper tissue used to form the lower web. 3 is the spool orcreel providing the plurality of glass strands. It! is the adhesivematerial in a suitable container into which the conveyor roller 7 dipsand carries adhesive to the applicator roll 8 which, in turn, appliesthe adhesive material to one face of the lower web 6, which passesaround the combining roller 12. At the same time, the glass strands 4are drawn from the spool 3 through the reed 13 and united with the lowerweb 6 and the upper web 2 as they pass through the combining rollers 11and 12. The resultant tape 14 is passed through the rubber-coveredrollers 15 and 16, which apply sufiicient pressure to the tape 14 so asto produce a series of corrugations in the tape 17. The tape may then bewound into a reel for subsequent storage or may be led directly to aconventional twisting machine. The reed 13 contains a great plurality ofdents through which the individual glass strands are fed so that thestrands are kept in parallel alignment as they are being positionedbetween the upper and lower webs 6 and 2. In Fig. 2, the symbol 7represents the adhesive conveyor roll carrying the adhesive 10 to theadhesive application roll 8. The adhesive is applied to the face of theweb 6 which is carried up and around the roller 12 and is combined withthe glass strands 4 and the upper web 2 as the three components arepassed between the combining rolls 11 and 12. The resultant tape 14 isillustrated in a partial section to show the individual strands 4embedded in paral lel relationship in the adhesive 10 on the lower web 6and covered with the upper web 2. In Fig. 3, the rubbercovered rolls 15and 16 apply sufiicient pressure to the tape 14 made up of the upper web2, the lower web 6, the glass strands 4, and the adhesive 10 so as tounite the individual components into a unitary structure which has aplurality of corrugations in parallel alignment produced by the presenceof the glass strands between the upper and lower webs. Fig. 4 shows aside elevational view of Fig. 3 in which the tape 14 passes through therubber covered rollers 15 and 16 to produce the desired corrugatedefiect. Fig. 5 represents one of the modifications of the processillustrated in Fig. l in which a lower web 6 is used as the sole web andupon which the adhesive is applied and the glass strands are embedded ina series of disconnected parallel groups, each of which can be separatedinto individual tapes at the lines 18 by some suitable cutting devicesuch as a cutting wheel. In mass production of the twine, one couldapply the adhesive 10 to the web 6, superimpose thereupon the glassstrands in a plurality of groups in parallel alignment. The web may becut along the lines 18 and the web 6 may be folded over the top of theglass strands in either a butting or overlapping arrangement. This ismore completely illustrated in Fig. 6. Therein one section of Fig. 5,which has been cut from the rest of the web, along at least one of thelines 18, illustrates the resin 10 coated on the web 6 and folded overin part and superimposed upon the resin covered strands 4. If one wereto practice the process of the present invention by adapting themodification illustrated in Figs. 5 and 6, one could dispense with theneed for the roller 11 and the upper web 2 but would need someconventional plow-like device to force the web 6 to fold up and over thetop of the strands embedded in the resin before passing through therollers 15 and 16 to produce the corrugated effect. Still further, theconcept illustrated in Fig. 5 could be further modified by applying theglass strands along the web 6 in parallel alignment without anyappreciable discontinuity between the groups of strands and bypracticing the process as illustrated in Fig. 1, an upper web 2 could beapplied to the assembly and the individual tapes out along lines such asthose indicated by the symbol 18 prior to or subsequent to the passingof the complete assembly through the rubbercovered rollers 15 and 16.Fig. 7 illustrates a sectional view in part of the combined assembly ofupper web 2, lower web 6, strands 4 and adhesive 10 prior to the passageof this combined assembly through the pressure rollers 15 and 16. It isto be noted that each group of filaments making up an individual strandof glass is completely surrounded by the adhesive material and eachstrand is kept separate from each other strand. It is to be furthernoted that since this tape has not been passed through the rollers 15and 16, the corrugations have not, as yet, been produced. Fig. 8illustrates the corrugated tape in an enlarged view, partially insection, which would be produced by passing a flat, composite tapecomparable to that illustrated in Fig. 6 through the rollers 15 and 16.Again, it is to be noted that the individual strands 4 made up of theindividual filaments are isolated from one another by the adhesive 10which, in turn, protects the strands from direct contact with the web 6.The point 20 shows the butting of the edges of the web 6. Fig. 9illustrates a substantially enlarged sectional view of one portion ofFig. 8, in which the filaments 19 making up the glass strand 4 are verynumerous but it is to be noted that the filaments in one strand areisolated from the filaments in the next adjacent straud. The adhesive 10not only separates the individual strands but also substantiallyprotects the strands from direct contact with the paper webs 2 and 6. InFigure 10 the symbol 4 represents the glass strands, 6 represents thepaper and 10 represents the adhesive bonding the glass strands and paperweb together.

In the practice of the process of thepresent invention any adhesivematerial may be used to bond the paper web and glass strands togethersuch as natural adhesives and synthetic resinous adhesives boththermosetting and a thermoplastic.

1,3,5-triazine and the like. Other thermosetting resins which may beused are those produced by the coreaction of an aldehyde with phenols;such as hydroxy benzene, Iesorcinol, bis-phenol and the like, oraldehydes reacted with ketones such as acetone, methylethyl ketone,diethyl ketone, ethyl propyl ketone, cyclohexanol and the like. Amongstthe aldehydes which may be used in coreaction with any of the resinforming materials set forth hereinabove are acetaldehyde,propionaldehyde, crotonic aldehyde, acrolein and aromatic orheterocyclic aldehydes such as benzaldehyde, furfural and the like.Formaldehyde is generaliy the most commonly used aldehyde in correactionwith these resin forming materials and is actually generally preferred.

Amongst the thermoplastic resin adhesives which may be used arepolyvinyl acetate, the alkyl esters of alpha, beta unsaturatedcarboxylic acids such as polymethyi acrylate, polymethyl methacrylate,polybutyl acrylate, polybutyl fumarate, alkyd resins of the unsaturatedor saturated type, either oil free or oil containing, modified withstyrene or other vinylidene compounds, polyesters such as glycolsuccinates, or glycol sebacates, amide esters and the like.

Rubber adhesives, both natural and synthetic, may be used, such as thepolymersof butadiene or copolymers of butadiene and styrene.

Amongst the natural adhesives which may be used are casein, soya proteinand other proteins, starch, animal glue, gelatin, blood, asphalt, pitchand the like.

The tapes produced according to the process of the present invention, inand of themselves, are extremely strong and useful even withoutsubjecting them to the twisting operation. in the preparation of thetapes for twine purposes, the paper should be tissue twisting paperwhereas for non-twine purposes any paper may be used.

When these tapes are desired in the twine form, they may be twisted in anumber of different ways, for instance, the tape may be passed through awater bath and then run directly to the twisting machine, or the tapesmay be merely passed between heated rollers and directly twisted or as afurther modification the tapes may be passed between a pair of parallelhot plates, and twisted directly. A still further modification can beaccomplished by applying heat, such as in the manners indicatedhereinahove, passed through a water bath and then twisted to form thetwine or the tapes may be passed through a water bath, twisted to formthe twine and then heated. A still further modification resides in thatembodiment in which a water bath is used wherein a sizing material suchas glue, flour, etc. is incorporated into the water bath. Still further,one could apply to the paper web a softener in the nature of an oil suchas mineral oil, vegetable oil or the like.

A still further modification of the general process itself resides inthe use of a third web of paper wherein a lower web, coated withadhesive is embedded with the parallel glass strands, a second web,coated with adhesive on both sides is superimposed thereupon, a secondlayer of parallel glass strands is embedded thereon and a top web ispositioned to form a sandwich-like structure of paper, adhesive, glassstrands, paper, adhesive, glass strands and paper.

The number of glass strands used across a given web is in no waycritical. It is possible to vary the number of strands rathersubstantially depending on the width of tape or thickness of twinedesired and depending further on the strength of tape or twine desired.

In the manufacture of the glass filaments, molten glass, maintained at atemperature of about 2500 F. is allowed to pass through about 204 diesto form glass threads which are drawn downward at about 6000 ft./rnin. Asize coating is applied to the individual filaments. This coating servesto protect each individual filament from its companions in the strandwhereby loss due to attrition is reduced to a negligible factor.

I claim:

l. A process for producing twine comprising the steps. of coating oneface of a tissue paper web. with anadhesive material, bysuperimposingand imbedding on said web a plurality of adhesivematerial-coated glass fibrousstrands, in parallel alignment, coveringthe strand. inrbedded, adhesive coated web with a tissue paper web anduniting these components into a fiat assembly, thereafter twisting saidassembly into a twine.

2. A process for producing twine comprising coating one face of a tissuepaper web with an adhesive material, superimposing on approximatelyone-half of the width of said adhesive coated web, a plurality of glassfibrous strands, in parallel alignment, folding the paper so as to coverthe strands to form a flat assembly, thereafter twisting said assemblyinto a twine.

3. A process for producing twine comprising coating one face of a tissuepaper web with an adhesive material, superimposing on approximatelyone-half of the width of said adhesive coated web, a plurality of glassfibrous strands, in parallel alignment, folding the paper so as to coverthe strands to form a flat assembly, pressing the folds of the paper webtogether so as to form corrugations with said strands and paper,thereafter twisting the paper-strand assembly into a twine.

4. A process for producing twine comprising coating one face of a tissuepaper web with a thermosetting synthetic resinous adhesive,superimposing on approximately one-half of the Width of said resincoated web, a plurality of glass fibrous strands, in parallel alignment,folding the paper web so as to cover the strands to form a flatassembly, thereafter twisting said assembly into a twine and heatingsaid twine so as to cure the resin.

5. A process for producing twine comprising coating one face of a tissuepaper web with a thermoplastic synthetic resinous adhesive,superimposing one approximately one-half of the width of said resincoated web, a plurality of glass fibrous strands, in parallel alignment,folding the paper so as to cover the strands to form a flat assembly,thereafter twisting said assembly into a twine.

6. A process for producing a glass strand and paper twine comprising thesteps of coating one face of a tissue paper web with an adhesivematerial, superimposing and embedding on approximately one fourth of thepaper web on each side of the center of said web, a plurality of glassfibrous strands in parallel alignment, folding over both sides of theweb not covered with strands onto the center portion of the web coveredwith the strands, uniting into a fiat assembly, thereafter twisting saidassembly into a twine.

7. A process for producing glass-paper twine comprising coating one faceof a tissue paper web with an adhesive material, superimposing andembedding on said adhesive coated web a plurality of glass fibrousstrands, in parallel alignment, covering the strand embedded adhesivecoated web with a second tissue paper web, and uniting these componentsin a substantially flat assembly, thereafter twistin said assembly intoa twine.

8. A thermosetting resin coated paper-glass strand twine comprising aplurality of spirally parallel glass strands positioned between at leasttwo layers of twisted tissue paper and embedded in a thermosettingsynthetic resin.

9. A thermoplastic resin coated paper-glass strand twine comprising aplurality of spirally parallel glass strands positioned between at leasttwo layers of twisted tissue paper and embedded in a thermoplasticsynthetic resin.

it). A composite cord formed from a tape comprising a plurality ofparallel glass strands positioned as a layer of substantially singlestrand thickness between at least two layers of paper and adhesivelybonded to said paper, said tape being twisted into cord configurationwherein substantially all of said glass strands are maintained inspirally parallel relationship in a single layer between any given twolayers of said paper.

11. Aprocess for producing twine comprising forming a tape by combiningtwo layers of paper and a plurality of glass strands positionedtherebetween in parallel relationship in a layer of substantially singlestrand thickness, adhesively bonding said strands to said paper andthereafter twisting said tape into a twine.

References Cited in the file of this patent UNITED STATES PATENTS CohoeOct. 10, 1939 Fay Aug. 18, 19,42 Horstrnan Sept. 19, 1950 Mathes July22, 1952 Slayter et al. Dec. 29, 1953 Slayter Mar. 9, 1954

1. A PROCESS FOR PRODUCING TWINE COMPRISING THE STEPS OF COATING ONE FACE OF A TISSUE PAPER WEB WITH AN ADHESIVE MATERIAL, BY SUPERIMPOSING AND IMBEDDING ON SAID WEB A PLURALITY OF ADHESIVE MATERIAL-COATED GLASS FIBROUS STRANDS, IN PARALLEL ALIGNMENT, COVERING THE STRAND IMBEDDED, ADHESIVE COATED WEB WITH A TISSUE PAPER WEB AND UNITING THESE COMPONENTS INTO A FLAT ASSEMBLY, THEREAFTER TWISTING SAID ASSEMBLY INTO A TWINE. 